渤海湾盆地中新生代扭动构造及其对油气的控制作用

渤海湾盆地在演化过程中经受了前期压扭和后期张扭构造应力场的作用,在边界断裂走滑作用及盆地基底块体转动的影响下形成了众多的扭动构造。对油气的形成、运移、聚集起着控制作用。其原因是渤海湾盆地正好处在全球走滑带的重要部位。中新生代的活动是全球走滑带构造活动的一部分。

THE ROTATION STRUCTURE OF THE BOHAI GULF BASIN IN THE MESO-CENOZOIC AND ITS CONTROL ON OIL-GAS DISTRIBUTION

The Bohai Gulf Basin is bordered by deep faults, such as Tancheng-Lujiang fault zone in the east, the east limb faults of Mount Taihang(Zijinguan faults)in the west,Baode-Changli faults in the north,Qihe-Guangrao faults and Huanghe faults in the south. Fault activities in this area show characters of inheritance. In the late Mesozoic (J-K), some faults around the basin, especially the NE-striking faults were mainlt compressive and sinistral. The hard basal block of the basin tended to rotate in a similar way. At the same time, surrounding block acted as obstacles. As a result, a series of compressive rotational structures were produced within hard basal block. In the Cenozoic, the main faulting activities were extensional and right-lateral strike-slip. The corresponding rotation of hard basal block happened again. So the compressive rotation structures occurred in the early period,and then turned into the extensional rotation structures,for instance,Hebei-Shandong Brush-structure (Liu Zerong, 1983),sub-rotation structure,e. g. Chaheji S-shaped Structure,Masi Brush Structure, Hejianxi Vortex Structure, east Shen County Brush Structure (Wu Jilong ,1986) and Xinlongtai Vortex Structure (Han Shuanmin, 1983). There are also a lot of an echelon faults-blocks, faults, and structure zones, and Lambda-type folds etc. These rotation structure play a main role in formation, migration, gathering of oil and gas.Abundance of the rotational structures within and near Bohai Gulf Basin results form the tectonic setting in a " global sliding zone" (. M. Pacyeemaeb, 1980, 1991). The Meso-Cenozoic activities are a part of global sliding, and this is a problem which needs more study.